Screening method and application of exogenous viscosity-reducing bacteria in heavy oil reservoir

The invention discloses a heavy oil reservoir exogenous viscosity-reducing bacterium screening method and application, and belongs to the technical field of oil exploitation. On the basis of indexes such as an emulsification index, an adhesion rate and endogenous-exogenous bacterium matching performance evaluation, exogenous viscosity-reducing bacteria are screened from a heavy oil well output liquid or a united station effluent water sample, and the adaptability of the exogenous viscosity-reducing bacteria of the heavy oil reservoir to endogenous flora is ensured through a flora compatibility experiment, so that the synergistic performance of endogenous-exogenous flora is effectively exerted, and the viscosity-reducing effect of the heavy oil reservoir is improved. The method has the advantages that the problem that the hydrocarbon and viscosity reduction activity is weakened or the effect is not ideal due to the difference of oil reservoir environmental factors of exogenous bacteria is solved, the viscosity